Source code for langchain.chains.sql_database.base
"""Chain for interacting with SQL Database."""
from __future__ import annotations
from typing import Any, Dict, List
from pydantic import BaseModel, Extra, Field
from langchain.chains.base import Chain
from langchain.chains.llm import LLMChain
from langchain.chains.sql_database.prompt import DECIDER_PROMPT, PROMPT
from langchain.prompts.base import BasePromptTemplate
from langchain.schema import BaseLanguageModel
from langchain.sql_database import SQLDatabase
[docs]class SQLDatabaseChain(Chain, BaseModel):
    """Chain for interacting with SQL Database.
    Example:
        .. code-block:: python
            from langchain import SQLDatabaseChain, OpenAI, SQLDatabase
            db = SQLDatabase(...)
            db_chain = SQLDatabaseChain(llm=OpenAI(), database=db)
    """
    llm: BaseLanguageModel
    """LLM wrapper to use."""
    database: SQLDatabase = Field(exclude=True)
    """SQL Database to connect to."""
    prompt: BasePromptTemplate = PROMPT
    """Prompt to use to translate natural language to SQL."""
    top_k: int = 5
    """Number of results to return from the query"""
    input_key: str = "query"  #: :meta private:
    output_key: str = "result"  #: :meta private:
    return_intermediate_steps: bool = False
    """Whether or not to return the intermediate steps along with the final answer."""
    return_direct: bool = False
    """Whether or not to return the result of querying the SQL table directly."""
    class Config:
        """Configuration for this pydantic object."""
        extra = Extra.forbid
        arbitrary_types_allowed = True
    @property
    def input_keys(self) -> List[str]: